Comment by voidUpdate

I may have had this happen without realising, but in my head, a tip is something you choose to add on extra, whether for good service or because the workers aren't getting paid properly. If I get a service charge, that's more like just part of the bill that I would pay, though I've only really noticed it as part of online stuff, for example my bank has a £25 service change to send money overseas (for some reason, I can't imagine that the process isn't fully automatic by now)